For the application of Gr.5 titanium alloy in additive manufacturing (AM), significant progress has been made in the research and application of Gr.5 titanium alloy in the biomedical, aerospace, and automotive industries. In the field of biomedicine, AM technology is widely used in the manufacturing of customized implants, including but not limited to dental implants, cranial prosthetic plates, mandibular prostheses, cervical fusion instruments, pelvic disc implants, hip and ankle prostheses, etc. Titanium alloys benefit from their excellent biocompatibility and mechanical properties, making them the preferred choice for implantable materials in the biomedical field. AM technology can customize. perfectly matched implants according to the specific situation of the patient, greatly improving the surgical effect and patient recovery speed.
In the aerospace field, AM technology is mainly used to produce components with extremely high performance requirements and extreme working environments, such as various engine parts and spacecraft structural parts. The use of AM technology can significantly reduce material waste and produce complex structural parts that are difficult to achieve with traditional manufacturing methods, improving part performance and significantly reducing quality, which is crucial for the aerospace industry in pursuit of ultimate efficiency and minimized energy consumption.
In the automotive industry, AM technology is mainly used in rapid prototyping, the production of complex or customized automotive parts. For example, brake calipers, movable rear wing brackets and tailpipe trim covers. In the field of racing design, weight reduction and improved design freedom are particularly key, and AM technology shows great application potential in this field. Through lightweight design, it can effectively improve fuel economy and reduce emissions, which is in line with the sustainable development goals of the automotive industry.
In the case of marine titanium alloy equipment, the unique conditions of the deep-sea environment, such as high hydrostatic pressure, low temperature, and low dissolved oxygen content, pose challenges to the corrosion resistance of titanium alloys used in underwater equipment. These factors can affect the corrosive behavior of materials, especially increasing the risk of localized corrosion and stress corrosion cracking. Pazhanivel study showed that the susceptibility of Gr.5 titanium alloy prepared by SLM technology was increased when the slow strain rate test (SSRT) was performed in the NaCl environment. This is mainly attributed to the increased corrosion susceptibility of the α/β phase interface and the formation of gasides. The rapid cooling rate in SLM technology promotes grain refinement, which, while improving the strength of the material, can also lead to an increased risk of stress corrosion cracking. In addition, electrochemical corrosion is also a problem for titanium alloys for deep-sea equipment, as it can lead to degradation of material properties and even jeopardize structural integrity. Zhou's research found that the corrosion resistance of Gr.5 alloys made by LMD technology with unidirectional or cross-scan paths is inferior to that of traditional forgings. Rapid cooling and uneven thermal gradients during LMD can lead to the formation of non-equilibrium phases such as α martensitic in the alloy, and the presence of this phase may reduce the alloy's corrosion resistance.
Despite the challenges faced by titanium alloys in the application of underwater equipment in additive manufacturing, this technology holds great potential to enhance its corrosion resistance, particularly in the marine sector. With the in-depth study of the impact of the deep-sea environment, it is expected that titanium alloy materials can be better developed and the development of deep-sea equipment technology can be promoted.
